Some Assembly Required
by Maks the Mushroom
Summary: San Fransokyo was theirs to protect, that much was certain. But when a Norse God comes to their world with an intent to conquer and rule, Hiro and his team are pulled into something so much greater than they ever imagined. (Takes place post-BH6 and before/during the first Avengers movie)
1. The Man with a Folder

**Hi everyone, I'm back again.**

**Should I be working on Three Seconds Longer? Yes, yes I should. However, I've had this idea stewing in my head for a very, very long time, and I just couldn't help myself. Merry Christmas, everyone!**

**Disclaimer: I own nothing.**

O-O

It was Hiro's second day of college.

His first day had gone without a hitch. Most of his teachers understood the reason behind his long absence and happily supplied him with the necessary makeup coursework, which to his joy was-at least, to him-relatively easy. He'd have it all done by the end of the week, tops.

The other students were surprisingly accepting, too. When Hiro walked into his first classroom, he expected the usual whispers and giggles and maybe some cooing from the female students-instead, hardly even anyone batted an eye. A few even recognized him from the Expo and asked him for help with designing their semester projects, which were so much more marvelously complex than anything Hiro had seen before, even in the botfighting rings.

But perhaps best of all, Baymax was still here.

He had found the green data chip clenched in the rocket fist while he was moving into his personal lab. Further rifling around his bedroom later that day recovered Tadashi's old notebooks, containing every blueprint, note, and schematic for the inflatable nursebot.

He could rebuild Baymax. Sure, it would be complicated, but he could do it. He had to.

There was a loud bang as the doors to his lab were unceremoniously thrown open. "Alright, this is the last one," Gogo announced, setting down the box next to the others and dusting off her hands. "Tadashi sure kept a lot of journals, didn't he?"

Hiro let out a wistful sigh. "Yeah," he muttered, drawing his fingers across the top of the box. "I always told him he should've gotten a tablet…"

"Hey." Gogo set a firm hand on his shoulder. "You gonna be alright?"

Hiro blinked up at Gogo, quickly shaking himself out of his reverie. "Y-Yeah, I'll be fine. Don't worry about me."

Gogo regarded him skeptically for a moment. "Well," she said at last, "just give us a call if you need us."

"I will," Hiro replied. "Thanks, Gogo."

"No problem." A playful smile pulled at the edge of her lips, and she reached over to ruffle his hair. "Now don't stay up too late, knucklehead."

"Agh, hey!" Laughing, Hiro swatted her hand away, trying (and failing) to make his hair lie flat again. "I won't, I won't!"

"Good." Gogo chuckled, popping her gum. "See you later, kid."

Hiro watched her leave with a smile before turning back to the mass of boxes scattered around his lab. While he had unpacked most of his stuff yesterday, today they had brought in all of Tadashi's old supplies to help him rebuild Baymax. Thankfully, all of the nursebot's coding was still intact on the green chip; all Hiro had to do was recreate Baymax's huggable design.

He had just begun poring over some of his brother's earliest design concepts when he heard the door to his lab open again. "Gogo," he said, spinning his chair around, "I told you, I'll be-"

Hiro stopped short. The man in the suit standing in his lab was definitely not Gogo.

"Mr. Hiro Hamada, I presume?"

The man stepped forward, his large forehead almost gleaming under the lab's fluorescent lights. His graying brown hair was slicked precisely back, and a crisp manila folder was tucked beneath his arm. Hiro could only nod his head warily in response.

"I am Agent Phil Coulson, of the Strategic Homeland Intervention, Enforcement and Logistics Division."

"Wow," Hiro remarked before he could stop himself. "That's a mouthful."

"We generally just go by SHIELD," Coulson conceded with a shrug. His expression grew serious again. "You were the leader of the team that stopped the incident at Krei Tech a few days ago, correct?"

Hiro's eyes grew wide. "What - how did you know that?!"

"Facial recognition software," Coulson answered easily. He began to flick casually through the contents of the folder. "That was some impressive work that day. We've never seen anything like it, especially not from someone of your age."

Hiro blinked in confusion, eyes flicking nervously between the man and the folder. "What's your point, sir?" he asked.

Coulson took a breath, carefully setting the folder down on Hiro's desk. "We would like you and your team to join the Avengers Initiative."

O-O

**Sorry it's short; it's a prologue and well, I'm just testing the waters with this fic. We'll see how well this turns out. Hope you enjoyed! Please review if you can!**


	2. Offers

**Look who finally updated!**

**Sorry everyone, but I had a severe case of writer's block. Not fun. But I've finally managed to crank out the next chapter so...yay!**

**Disclaimer: I own nothing.**

o-o

Hiro blinked in confusion, slowly processing what Coulson had said. "The...Avengers Initiative?"

Coulson nodded. "It's a project designed to assemble together a group of highly skilled individuals that would respond to any global threats, should they arise," he explained. "With you and your team's technical prowess and fighting capability, you're the perfect candidates."

Carefully, Hiro picked up the folder Coulson had placed on his desk, curiously flipping through its contents. He recognized a few of the people - renowned genius industrialist Tony Stark, for one - but most were complete strangers. The profiles accompany each candidate were insane; sure, the words on the page made complete sense to Hiro, but the sheer statistical improbability of these abilities had to be seen to be believed. Then again, Hiro hadn't been one to follow the general convention of things, either…

"You want us to join...all this?" he asked, looking up at Coulson with wide eyes.

The agent nodded again. "We know it's a lot to ask, considering your age and the fact that you're still in college-"

"No, no!" Hiro interrupted. "It's not that, it's just…"

His eyes glanced over at the piles of notebooks still waiting to be shelved. Baymax still needed to be rebuilt, and without the inflatable robot around, the team just didn't feel...complete. The green data card glinted in its protective case next to his laptop, his brother's name printed neatly across the front.

Before anything, Hiro needed his best friend back.

"Thank you, sir," the young boy said at last, handing Coulson back the folder, "but I'm afraid I'll have to pass on your offer."

Coulson's lips pressed into a thin line. "I figured as much," he replied, tucking the folder back under his arm. "But still, the offer remains, should you change your mind."

With a courteous smile, the agent ducked his head and exited the lab. "Have a nice day, Mr. Hamada."

o-o

"_Once again, our resident mysterious team of heroes saves the day, stopping an armed bank robbery on Ichiba Street…_"

Hiro leaned back in his seat, discreetly watching the cafe's TV screens through the corner of his eye. Four months had passed since the battle at Krei Tech, and well...life had taken an interesting turn, to say the least. No one in the group of friends really expected to ever suit up again after the fight, but when news of a hostage situation in downtown reached their ears one day, not a single one of them hesitated. That one incident became two, which quickly became ten, and soon, the six heroes - it had taken several sleepless weeks, but Baymax had finally rejoined their ranks - were the talk of the city.

No one suspected the five nerds and one giant marshmallow robot sitting at a table in the corner of the Lucky Cat Cafe were the ones behind the renowned team.

"_...according to sources, this marks the fifteenth time the team, dubbed 'Big Hero 6' by the public…_"

"Big Hero 6," Gogo snorted under her breath, shooting the news reporter on screen a brief glare. "Who even came up with that?"

"I dunno, man," Fred barely managed to mumble out through a mouthful of food, "I think it's got a nice ring to it. Like a comic book."

Wasabi shot him a look. "You think everything's like a comic book," he pointed out.

Fred jabbed a finger in Wasabi's direction. "No, I-"

_Beep_.

The group froze in surprise. "Baymax...?"

_Beep_.

"Hiro," the robot intoned, tilting his head slightly. A large red telephone symbol was being projected onto his stomach. "You have an incoming call."

Hiro frowned in confusion and glanced questioningly around at his friends. In unison, all shook their heads. "It's not us, dude," said Wasabi.

"Maybe it's your aunt?" Honey suggested.

Carefully, Hiro leaned over in his seat to see his aunt, who was happily chatting with a customer as she prepared their coffee. No one else had his cell phone number...well, except for Tadashi, but he wasn't exactly in a position to call him...

"Hiro," Baymax said again, this time more urgently, "my protocol is being overridden. It is required that you answer your phone."

Eyes wide, Hiro hurriedly fished his phone out of his pocket and jammed it to his ear. "Hello?"

"On your left, third booth."

Warily, Hiro turned in the direction he had been told, nearly falling out of his seat in shock. Sitting there was the man in the suit, his hair still slicked precisely back and another folder on the table in front of him.

"Is everything alright, Hiro?" Honey asked, leaning over onto the table.

"Y-Yeah," Hiro answered distractedly. "I'll just...I'll be right back."

Quickly, he hung up the phone and hurried across the room, sliding into the booth's unoccupied seat. The man peered at him over the edge of his sunglasses.

"So...Big Hero 6."

"Was it really necessary to hack past my robot's protocols?" Hiro asked irritably, crossing his arms.

Coulson shrugged. "You wouldn't have answered any other way."

Hiro huffed but didn't disagree. "So...what do you want this time?" he finally asked.

With a thin smile, Coulson slid the folder across the table. "You and your team have been making quite a lot of headlines recently," he began, shooting a brief glance over at the TV screen. "Too many, in fact. You've caught the attention of several other organizations outside of SHIELD, some good, others...not so much."

Hiro quickly flicked through the contents of the folder. "Your point is?"

"My offer to join the Avengers Initiative still stands," Coulson said. "Of course, you'd be operating under SHIELD, but we could help keep a few other...interested parties off your trail."

Hiro frowned and glanced over at his friends, who were all furtively trying to eavesdrop on their conversation. "Can I talk to my fri- my team for a moment?"

Coulson leaned back in his seat. "Be my guest."

With a short nod, Hiro grabbed the folder and walked back to the group. "Hiro, are you okay?" Honey asked him worriedly.

"Yeah, I'm-"

"Who was that?" Wasabi cut in.

"Dude," Fred added, "is he some secret sort of spy agent man?"

"Hiro, my sensors detect high levels of-"

"Guys, guys, I'm fine!" Hiro shook his head, rolling his eyes ever so slightly. Sometimes his friends worried way too much. "That man's Mr. Phil Coulson from some SHIELD...agency...thing…"

"Wait, you mean like the government?" Wasabi asked.

Hiro shrugged. "Yeah, he visited me a few months ago and-"

"He's talked to you before?" Gogo interjected. "Why didn't you tell us?!"

"I was busy rebuilding Baymax, okay?!" Hiro replied defensively. He ran a hand through his messy hair, quickly explaining the situation to the group. "So...what do you guys think?" he asked at last.

There was a loud pop as Gogo smacked her gum. "No. Way."

Wasabi nearly spit out his drink. "Wh-What?!" he spluttered frantically, his voice jumping up an octave. "N-No! You can't just say no to the government!"

"How do we know we can even trust the guy?" Gogo continued. "_He knows our secret_. No one should know that."

"It's the government!" Wasabi stressed. "Do you know what the government does when you say no?"

Gogo rolled her eyes. "Oh calm down, you big baby. We'll be fine."

Baymax tilted his head to the side, blinking curiously at Hiro. "Will joining the 'Avengers Initiative' make me a better healthcare companion?" he asked.

"I don't know, buddy," Hiro replied. "Maybe."

"Wait," Fred piped up, eyebrows furrowed together in thought, "did 'SHIELD' stand for anything?"

"Uh, yeah, I think so." Hiro pushed his bangs from his forehead as he tried to remember. "Strategic Homeland...Intervention…"

"Enforcement and Logistics Division," Fred finished easily. "My dad told me about them. According to him, they're a very secretive organization. They don't like telling the truth."

"So you think they're lying about this?" Honey asked.

"Who knows," Fred replied with a shrug. "But I'm with Gogo on this one."

Gogo raised an eyebrow, popping another bubble. "Thanks...I think."

"Excuse me, Mr. Hamada?"

Hiro turned around to see Coulson standing a ways behind him, an oddly apologetic smile on the agent's face. "My director just called. I'm needed back at base immediately." He shot a quick glance at the group assembled around the table. "I assume you've made your decision?"

"Oh, uh...yeah." Fumbling slightly, Hiro handed back the folder for a second time. "Thank you, sir, but we're not interested." Behind him, Wasabi made a tiny squeak of protest, but Gogo shushed him.

Coulson nodded his head, tucking the folder into his jacket. "Very well then."

And with that, he was gone.

o-o

In hindsight, Hiro probably shouldn't have started his final project so late.

To be fair, it wasn't entirely his fault. The team's suits needed some serious upgrades, and by the time he had finished that, he had approximately two weeks left to design and built something amazing for the year's final showcase. Which honestly shouldn't have been that hard...except for the fact that he was suffering from a severe case of designer's block.

"Nothing!" he moaned, slamming his forehead against the lab desk. "No ideas! Stupid, empty brain!"

"I would suggest not hitting your head against that," a voice said. "It damages the brain cells."

Hiro shot up in his seat, scrambling to grab a wrench to defend himself with. He was greeted with the familiar sight of a man in a suit in his lab, folder in hand.

"Oh, not you again," he groaned, letting the wrench clatter to the floor. "I told you last time, we don't want to join your Avengers Initiative. Now would you leave me alone?"

"This isn't about the Avengers Initiative," Coulson said, stepping over the boy's cluttered workbench. "That was actually shut down a while ago." He carefully approached Hiro's desk and held out the folder. "This is an offer specifically for you."

Hiro frowned, cautiously taking the folder and flipping through the contents. "For me?"

Coulson nodded. "It's called Project PEGASUS, a search for alternative energy sources," he explained. "Currently, they're experimenting with an alien artifact called the Tesseract."

Hiro looked up from the files. "You're trying to harness energy from space?" he asked.

Again, Coulson nodded. "We think this might be the key to unlimited sustainable energy, but we've reached a bit of a rut in the calculations. And, as one of the brightest new scientists of the decade, we figured you were the ideal person to help."

"But...I don't know anything about interdimensional physics," Hiro pointed out.

"I'm sure you'll learn quickly." The agent smiled warmly at the young boy, locking tired grey eyes with brown. "If this works, it could help a lot of people."

Cold ice instantly flooded Hiro's stomach. Distantly, he could hear his brother's voice echoing in his mind. "What- What did you say?"

"This could help a lot of people someday," Coulson repeated. "Unlimited sustainable energy. Less pollution, greener cities…" He trailed off, shrugging his shoulders. "So, what do you say?"

Hiro's grip on the folder tightened, and he swallowed back the lump in his throat.

"I'm in."

o-o

**And there you have it folks! I apologize if this isn't exactly quite what you were expecting, but I hope you liked it nonetheless. Next chapter we should be seeing more Marvel characters and maybe a bit more action. (Speaking of next chapters, don't expect another update for another month or two. I'm a terribly slow writer.)**

**Hope you enjoyed! Please review if you can!**


	3. Coffee and the Occasional Cat Statue

**Guess who finally made a comeback?!**

**Yes, I'm alive. Yes, I have the same laundry list of excuses as usual. Yes, I'm terribly sorry.**

**But thankfully, AP testing is almost over, which means I should have more time to write. Will this mean that I will actually publish chapters at a faster rate? ...eh, we'll see. But I'm trying.**

**On another note, we introduce another Marvel character to this universe in this chapter. You'll notice that I went more with the comic book portrayal of him rather than the movie, and I also included his disability. That version of him fit better in the universe I'm creating than the more stoic version of him that was shown in the movie. But I will be incorporating some of his movie self in here too.**

**As per usual, I own nothing. Enjoy!**

o-o

For the record, Clint Francis Barton had done many crazy things in the name of SHIELD. He'd broken past one of the world's highest security vaults. He'd jumped out of the window of a 50-story building. He'd even guarded an alien hammer that fell from the sky.

But this - this had to be one of the strangest things he had ever been asked to do.

"Wait, so let me get this straight: you're asking me to pick up a _kid_?"

"A fourteen year old boy, yes." Coulson said as he finished loading the data into the tablet. He handed it to the other agent with a smile. "To be fair, he's also a genius scientist," he amended sheepishly, "but yeah...a kid."

Clint pressed his lips together in annoyance, lazily flicking through the kid's file. "No offense, sir, but why aren't you doing this?" he asked. "I always pegged you as the soccer mom type."

"Fury wants me to stay on base," Coulson explained with a shrug. "I'm acting second in command while he's reviewing the situation in Budapest."

"Ah."

A frown crossed the archer's face as he looked over some scans of newspaper articles. A few of the headlines were academically related - the boy received a grant, a new building opened at the city's polytechnical college in honor of his brother - but most spoke of a group of masked heroes saving their city from a variety of dangers. One of whom happened to be the scrawny little Asian boy he was being asked to pick up.

"...he's not _just_ a kid genius, is he?" Clint asked, raising an eyebrow.

Coulson simply smiled.

o-o

"_The Lucky Cat Cafe_?" Clint muttered to himself, surveying the building across the street. "What kind of name is that, anyways..."

Honestly, Clint had expected more from the home of a full-time kid genius part-time superhero. This place just seemed too...normal. No gadgets flying around the street corner, no random explosions, no high-tech security system; just fading paint, a few chipped roof tiles, and a sign in the window saying the place had been voted the best cafe in San Fransokyo.

The agent double checked the address one more time before crossing the street, dodging around one of the red trolleys rattling by. Instantly, the scent of coffee and sweet pastries filled his nose, and his stomach growled in appreciation. Patrons bustled in and out of the small cafe, chattering happily with food in hand. A few had settled into the tables beside the wide, crooked windows to watch the slow traffic roll by.

So maybe it wasn't exactly the home of a superhero genius, but hey, it looked like that sign in the window had some merit after all.

Carefully, Clint eased into the crowd and slipped inside, eyes automatically scanning the room for possible threats. He quickly relaxed, though; the only dangers here were hot coffee and the occasional cat statue.

"Hello, welcome to the Lucky Cat Cafe," the middle aged woman behind the register greeted. "How can I help you?"

"Um, I'll get a large coffee," Clint replied, fishing out his wallet. He hesitated for a moment before continuing quietly. "Also, do you know where I could find Hiro Hamada?"

The woman's wide green eyes crinkled up into a smile. "Oh, you must be the one who's picking him up today!" she exclaimed. She pointed towards the back of the cafe. "Just wait over there by the stairs. He'll be down in a minute."

Clint nodded his thanks and followed her directions to the back. Here, the chaos of the cafe gave way to a different kind of chaos; family pictures hung haphazardly on the walls, and metal parts were scattered about the floor. The place felt worn down and lived in, laden with memories.

"Aunt Cass!" a boy's voice shouted, the sound of his feet pounding on the stairs echoing through the room. "Do you know where my - oh."

The boy froze mid-step, staring at Clint with wide brown eyes. He matched the photo in his file exactly: wild mop of dark hair that seemed to defy gravity, scrawny limbs, battered blue hoodie. The agent offered him a friendly wave, leaning against the wall.

"Take your time, kid," he said. "We're not really in any hurry."

The boy blinked at him a few more times. "You're...not Mr. Coulson."

Clint bit back a laugh. "No, I'm not," he agreed. "The name's Clint Barton. I'm the replacement Coulson for today."

The boy nodded in understanding, a crooked smile playing on his lips. "I'm Hiro Hamada," he replied (though it was completely unnecessary; Clint knew who he was). "I, uh, I just have to finish packing a few things, and then-"

There was a loud thud from upstairs. "Hiro," a robotic voice called. "I have located the bag you were looking for."

Hiro visibly cringed. "...I'll be right back," he said, shooting Clint an apologetic look before rushing up the stairs.

A few minutes later, he returned, carrying a backpack and a small suitcase. "Okay, I'm all set."

Clint eyed his bags skeptically. "Is that all you're bringing?" he asked.

"Oh, no," Hiro quickly replied. "Baymax is carrying the big one."

Clint frowned. "Baymax?"

The (very loud) sound of vinyl squeaking together suddenly filled the hall, and Clint watched with mild surprise as a massive white balloon-shaped robot slowly began to descend the stairs. (It's certainly not the weirdest thing he's seen.)

"So...Baymax is...your robot butler," he said.

"Robotic nurse, actually," Hiro corrected. "My brother made him."

Clint nodded slowly, eyes still fixed on the robot. "So...is he almost done, or..."

"Yeah, just give him a few seconds."

Clint found that hard to believe. Baymax was only on the third step.

o-o

Finally, Baymax reached the bottom of the stairs, setting the luggage beside Hiro. "Here is your bag, Hiro," the robot remarked.

The boy flashed him a grateful smile. "Thanks, buddy." He turned to Clint. "Baymax, this is Mr. Clint Barton. Mr. Barton, this is Baymax."

Baymax seemed to be studying the archer, his "eyes" - hyperspectral cameras, really - blinking twice. A light blue projection suddenly appeared on the robot's rotund stomach.

_Hello_, it read. _I am Baymax, your personal healthcare companion. My scan has indicated that you have a moderate hearing disability. Will these captions help?_

Clint let out an impressed whistle. "Wow."

"Yeah, pretty neat, huh?" Hiro remarked, grinning proudly. "He's got a database of over 10,000 medical procedures, and I'm still upgrading him."

Baymax tilted his head to look over at Hiro. "Hiro, are you sure you do not wish for me to accompany you?" he asked. "My scan has also indicated trace amounts of radiation on Mr. Barton. I do not want you to get hurt."

Hiro nodded, a sad smile flickering across his face. "I told you, buddy, you need to stay here. More people here need your help. And besides," he shot the robot a knowing look, "you'll still be able to watch out for me."

Baymax considered what the boy had said for a moment before relenting. "...I will miss you, Hiro."

Hiro smiled, rushing over to hug the robot tightly. "I'll miss you too."

"Are you guys almost ready?" The woman from before peeked her head into the room, wiping her hands on a dish cloth.

Hiro nodded. "Yeah, we're almost done, Aunt Cass."

The woman leaned up against the doorframe, tossing the towel over her shoulder. "Now, are you sure you have everything?" she asked.

"Yeah, I'm-"

"Toothpaste?"

"Yes-"

"Shampoo?"

"Yes-"

"Extra pair of underw-"

"_Aunt Cass_."

"Sorry!"

Cass smiled apologetically, trying to contain her nervous bouncing. "It's just..." She released the squeal she had been holding back and yanked Hiro into a hug. "My little nephew's going off to some secret base for who knows how long, and I don't even know where it is, let alone the dangers-"

"Aunt Cass, I'll be fine!" Hiro smiled up at her, gently worming his way out of his aunt's arms. "You know me, I got this."

Cass took a step back, biting her lip. "I know."

Hiro gave her another reassuring smile and picked up his luggage. "Alright," he said, turning to Clint. "Let's go."

Clint nodded, helping him with the bigger bag. "The car's just across the street," he said. "Sorry I couldn't find better parking."

Hiro shrugged. "It's fine."

"Hiro," Baymax called, waddling over, "I will contact your friends at the university and tell them you are departing safely."

Hiro smiled gratefully up at the robot. "Thanks, buddy." He paused for a moment in front of the doorway, then he dropped the bag he was carrying and ran back to Cass, engulfing her in a tight embrace. "Last hug!"

Happily, Cass returned the gesture. "Alright," she said, letting Hiro go. "Now go save the world."

A wide smile tugged at the young boy's mouth, and he sprang back to Clint's side, picking up the bag brightly. "You sure you're ready, kid?" Clint asked.

Hiro nodded. "You bet I am."

It was only three hours later, when he was sitting on the helicopter that would take them to the PEGASUS base, that Clint realized that he never actually did get his coffee.

o-o

"...the cafeteria is on the ground level, and the lab you'll be working in is at the very bottom of the facility. Unless told otherwise, you are not allowed in any other areas. Got it?"

Hiro nodded, really only half-listening to Clint's spiel as they walked through the halls. Despite the base's housing being above ground, everything still had that cold, cramped feeling to it. Cameras sat in almost every corner, and personnel bustled to and fro past them, tablets and clipboards in hand. Almost everyone wore the same uniforms too: form-fitting navy blue jumpsuits with a black eagle patch on the arm. Hiro seriously hoped they wouldn't make him wear one of those - Gogo would never let him hear the end of it.

Clint suddenly stopped walking, casually swiping a key card on one of the doors. "And this is your room," he said, flashing Hiro a smile. "They're expecting you down in the lab in an hour, but honestly, you can take your time. Any questions?"

"Uh, yeah." Hiro's lips curled up into a cocky smirk. "What's the wifi password?"

Clint rolled his eyes. "R-T-A-C-3-R," he recited. "Anything else?"

"Nope."

"Good." Clint pushed open the door and nonchalantly dragged Hiro's big bag inside. The room wasn't too bad; it was a little smaller than Hiro's half of the bedroom back in San Fransokyo, with a small bed shoved into the corner and a desk up against a wall. Hiro noticed with disdain that a tiny security camera sat in the upper corner of the room.

"Well, I guess I'll leave you to get settled in," Clint said, flashing Hiro another grin. "I'll be around if you ever want to, you know, talk or something. It can get boring here."

Hiro smiled gratefully at the agent. "Thanks."

The door clicked closed, and the expression immediately dropped off Hiro's face. Quickly, he yanked his laptop from his bag, all but throwing it onto the desk.

"Okay," he hummed thoughtfully, fingers flying across the keys. "Let's see how tough SHIELD security actually is."

_Camera in Room A113: Disabled._

_Bypass main frame._

_Network: Incognito._

_Internet: Enabled._

_Video Chat: Enabled._

A triumphant smirk tugged on his lips as the screen on his laptop filled with the faces of his friends, all huddled around the monitor in his garage workshop.

"Hiro!" they all cheered.

"Hey guys." Hiro grinned at them, leaning back in his chair. "Sorry it took me awhile, they're crazy paranoid over here."

"Told you," Fred quipped from his corner of the screen.

"Sorry we couldn't come and see you off earlier, Hiro," Honey apologized earnestly. "The professors insisted that we needed to stay in class to work on our showcase projects."

Hiro chuckled and shook his head. "It's fine, don't worry about it." His expression turned slightly more serious. "Is Baymax there?"

The four moved aside, and the screen suddenly filled with a large white vinyl belly. "I am here, Hiro," the robot replied from off-screen.

A loud laugh escaped the young boy. "Alright, good." Quickly, he rolled up the right sleeve of his hoodie, revealing a metal band clamped around his wrist. "How's the signal holding up?"

There was a pause. "The signal is holding steady," Baymax finally reported. "I can view all of your vitals from the wristband." Another pause; Hiro could almost see Baymax's (hypothetical) frown. "Your heart rate is faster than normal, and you have a high level of adrenaline."

"Sorry," Hiro apologized with a shrug. "Hacking does that."

Gogo moved back on screen, popping her gum. "Are you sure this is a good idea, Hiro?"

"Of course!" Hiro replied. "You guys were the ones who wanted to watch out for me, remember?"

"Yeah, but still..." Gogo frowned. "What if something goes wrong?"

Hiro rolled his eyes. "Aw c'mon, what's the worst that could happen?"

o-o

**...and there you have it!**

**If it wasn't clear in the chapter: Clint is at least partially deaf in this universe, Baymax stayed behind in San Fransokyo because Hiro insisted that he could help more people there than at the base (with Big Hero 6 and all), Hiro's fancy new wristband is connected to Baymax and monitors his health so that his friends can sleep easier at night, and SHIELD security is not Hiro-proof. If any other questions are left...well, I'm a writer. I can't reveal all of the story's secrets, now can I?**

**Thank you for reading, please review if you can!**

**Also happy Mother's Day to my mom.**


	4. Portals, Why Did It Have to be Portals?

...and voila! New update!

Sorry, I had writer's block for the longest time. Let's just say that taking Hiro out of his usual environment of friends and family and chucking him straight into the middle of a bunch of SHIELD personnel is hard to write; basically, in this chapter it's a lot more of Hiro acting as a professional and as a hero rather than the spunky goofball we all know.

BUT, it's still fun and exciting, and finally we actually kick off the plot of the Avengers movie. You'll probably notice that I took some liberties here and there instead of following the movie's script directly. This is because I'm combining the two universes, and when you plop characters and elements into a story where they weren't there originally...let's just say a lot of things can and will be affected. It's like throwing a stone into a pond (cheesy analogy, I know); there will be lots of ripples.

Anywho, on to the story! Hope you enjoy!

o-o

Hiro learned three very important things during his first week on base.

One: coffee is love, coffee is life.

Two: most agents really weren't too happy with the idea of having a young teenager among them.

Three: the Tesseract is a very, _very_ dangerous alien object. And it did not like being on Earth.

"What were the readings on that pulse?" Hiro called out, fingers flying over the computer keys.

"We can't tell," one of the scientists shouted in response. "It keeps fluctuating."

Hiro scowled, shooting a glare at the glowing blue cube in the center of the room. He was used to working with robots and mechanics, with things that actually cooperated with him and gave him steady data to work with. This - this endlessly _infuriating_ object - had given him nothing but headaches. And possibly a few gray hairs, according to Clint.

With an exasperated groan, Hiro pushed his rolling chair to another station across the room, glancing over the data on that monitor. "Do you at least have an average I can work with?" he asked.

The scientist hummed thoughtfully, pushing his glasses up the bridge of his nose as he scribbled down a couple of calculations. "Here, I think," he said, handing a clipboard to Hiro. Just then, the monitor showed another spike in the Tesseract's energy, and both let out another groan.

"Well, thanks anyway," Hiro replied, scooting back over to his usual station. Wearily, he took another sip from his coffee cup (Aunt Cass would kill him if she found out how much he had consumed in the last hour alone) and flipped open his laptop.

"Mr. Hamada," a voice suddenly called out. "Have you got anything new for me?"

Hiro spun around in his seat, one eyebrow raising at the (now familiar) sight of an elderly man dressed in plaid walking over to his station. "No, Doc," he replied. "The cube's still acting up. We can't get a good reading."

Dr. Selvig's brow creased into a frown. "What about the containment field?"

Hiro pressed a couple of keys on his laptop, and a large loading bar appeared on screen. "I'm calibrating the emitters right now," he said, chewing on his lip in thought. Wasabi's plasma blades had inspired the mechanism, but Hiro was used to working with the neat-freak's crazily precise calculations, not some weird glowing blue space cube that basically did whatever it wanted, whenever it wanted. "The magnetic field generated should be enough to keep the energy levels steady."

"'Should'," Selvig echoed. "Now that's the key."

"Hey," Hiro shot back defensively. "My tech always works. _Trust_ me."

The laptop beeped twice, and Hiro grinned triumphantly, disconnecting a large metal ring from the computer. "Alright, let's set this bad boy up."

Carefully, the two attached the ring to the compact muon solenoid coil chamber holding the Tesseract, the machine's lights and buttons blinking to life as Hiro ran a few final checks. "All systems are clear," he announced, settling down with his laptop. "Now let's just hope this works."

With a tense frown, Hiro punched a few buttons on his keyboard. Immediately, the machine began to hum, and a thin, shimmery white field appeared over the Tesseract.

"Levels are holding steady," a scientist called out from the other side of the room, and Hiro couldn't help but smirk.

"See," he said, glancing up at Dr. Selvig. "Told you it would - "

There was a loud boom, and the metal ring shattered in a pulse of blue light.

"'Always works', huh?" Selvig asked with a raised eyebrow.

Hiro shrugged sheepishly. "Eh..._most_ of the time."

o-o

Clint sat hunched in his little "nest" over the laboratory, eyes trained on the dark blue hoodie that stood out so clearly in the sea of white labcoats bustling around. The young teen didn't seem all that fazed by the situation - frustrated and annoyed, yes, but not fazed in the slightest. Clint could see him relegating orders to some of the other scientists and discussing possible scientific solutions with Dr. Selvig that would probably fry any normal person's brain; the kid was a genius, and more so, a natural leader. No wonder SHIELD had wanted him so badly.

(Well, that and the fact that he led one of the most prominent superhero teams in America...but that was technically classified.)

A frown crossed his face as he spied Hiro glancing up in his general direction. Quickly, he zipped down from his perch and padded over, arms crossed over his chest.

"What's up, kid?" he asked, peering at the teen's laptop.

"The cube's still acting up," Hiro replied. "Dr. Selvig and I don't know if it's even stable anymore."

Okay, that grabbed Clint's attention. "Stable? What-?"

"We've tried everything," the teen continued, rushing between monitors and typing in a few more values. "Containing it, shutting it down - nothing's working. It keeps going haywire." He ran his hand through his messy hair as he pulled up a few more blueprints on his laptop. "Someone's messing with it."

_Messing with it?_ Clint's frown deepened. "Well, from what I can tell, no one here's doing anything," he remarked, pressing his lips into a thin line. "Must be on the other end."

Now it was Hiro's turn to frown. "What 'other end'?"

"Selvig didn't tell you?" Clint asked. "Legend has it that the Tesseract is a doorway to the other end of space."

Hiro's eyes went wide. "A portal…" Hurriedly, the teen all but yanked his laptop over to him, hands flying over the keyboard. "No, no, no…"

With a swipe of his hand, the image on the laptop's tiny screen transferred onto the big monitor, displaying the blueprints and wreckage of two massive metal rings. In the corner sat a logo of a red bird soaring through a circle, and just beneath that, video footage of the events at Krei Tech almost a year ago.

"'Project Silent Sparrow'," Clint read aloud.

"That was the last time someone tried harnessing portal energy." Hiro's tone seemed darker, his eyes glaring coldly at the screen. "It...didn't go so well. If this is the same thing-"

"Or worse," Clint interjected.

"-then a lot of people could get hurt." With a heavy sigh, Hiro pushed himself away from the monitors. "We need to get everyone out of here. I'll talk with Dr. Selvig and see if we can stop the cube from forming that…'doorway' or whatever, but in the meantime, everyone needs to find a safe place."

Clint nodded sharply. "I'll tell Coulson to order evac," he said.

Hiro flashed him a tense but grateful smile. "Thanks."

"And hey," the agent added, clapping the younger boy's shoulder, "for the record, good luck." He took a deep breath. "...looks like you're gonna need it."

o-o

"Doctor, it's spiking again."

Dr. Selvig let out a tired huff and hurried over to the scientist's station, examining the readings on the Tesseract with worried eyes. The energy pulses were getting steadily stronger by the minute; he didn't know what would happen when it reached peak levels, and quite frankly, he wasn't sure he even _wanted_ to know. Across the room, Hiro was all but flopped over in his swivel chair, spinning aimlessly as he tried to come up with a viable solution.

"See?" the frustrated teen finally groaned out. "This is why we don't mess with _portals_!"

"Hey, it's alright," Selvig tried to reassure him. "We'll figure out a way to contain it." He quickly strode over to where Hiro sat, hands on his hips. "Have you finished the calculations yet?"

Hiro sighed and pulled up the values on the monitor. "I tried, but they came out the same as the Silent Sparrow numbers. And we all know how well _that_ worked out."

Selvig pressed his lips into a thin line, patting Hiro's shoulder. "Keep working. We're bound to find something."

There was the sudden sound of the heavy lab doors opening. "Alright, boys," a deep voice called out. "What have you got for me?"

"The Tesseract - she's misbehaving," Selvig answered.

Hiro raised an eyebrow. "Wait, since when has _it_ been a '_she'_?" he asked.

"She's an energy source, isn't she?" the doctor replied. "She's alive, pulsing-"

"And from what I heard," the voice interrupted, "causing you two a hell of a lot of trouble."

Hiro took a deep breath and finally turned around, glaring straight Nick Fury, director of SHIELD (he was a lot taller than Hiro that thought he would be...and the eyepatch was very unsettling). "What you're dealing with is portal dynamics," he said. "You can't control energy like that, let alone contain and harness it!"

"Normal people can't," Fury corrected. "But you can."

"Director," Selvig interjected, walking over to the other man's side. "The Tesseract seems to be...tampering with our plans to control her. She's throwing off interference: low levels of radiation, energy pulses, etcetera. Hiro here says there's a possibility she might blow."

"Well then let's pull the plug and move," Fury snapped.

Selvig shook his head. "Can't do that. She's turning the power back on every time we try. And our calculations aren't ready to formulate a harness yet."

Fury grit his teeth together. "Well then-"

"Doc!" Hiro shouted from his station, eyes trained on the screen and growing wider by the second. "Th-The energy levels are spiking. We might reach peak level."

In the middle of the room, the Tesseract began to thunder and shake. Massive blue arcs of energy lashed out in every direction, churning and whirling together like a brewing hurricane. Hiro instantly grabbed a hold of a table leg (there was no way he was flying off into another portal), and Selvig cautiously backed up a few paces.

Suddenly, a colossal beam of light blasted forth from the Tesseract's chamber, culminating in a swirling vortex at the far end of the room. For a moment, Hiro swore that within the blast he could see the vastness of space, dotted by thousands of stars...and then the whole thing exploded, wisps of blue energy soaring across the room.

And then...nothing. No explosions, no thunderous shaking. Only the sound of heavy breathing coming from the room's newest occupant.

The man seemed tall, with long black hair and a sneering grin; his pale skin glistened beneath the blue light of the Tesseract energy and his eyes glittered with malice. Even hunched over, he carried himself with an air of imposing regality, his long leather coat sweeping the now-burnt floor of the facility. In his hand he clenched a long, golden, spear-shaped object crowned with a glowing blue stone.

"Sir," Fury called out, hands raised in a gesture of peace. "Please, put down your weapon."

The man's head shot up, and the sneer dropped off his face. With a low growl, he swung out his spear, causing a blue arc of energy (not unlike the one just emitted by the Tesseract itself) to lash across the machines.

Hiro instantly darted under the desk. His eyes scanned over the room, desperately searching for something - _anything_ \- that he could use to help. He saw Clint, who had rappelled down during the commotion and now had his gun drawn, and Dr. Selvig, who was crouched over one of the scientists who had been struck by the blast. Panicked gunshots rang in his ears, but they were drowned out by the blasts of the man's spear, followed by cries of pain.

His gaze finally landed on the blinking fluorescent lights above them. "Wait…" Hiro frowned in thought, an idea building in his head. Hastily, he jumped up and snatched his laptop from the desk, beginning to type madly. "C'mon, c'mon, c'mon!" he quietly begged the lines of code racing across the screen. "...there!"

He pressed one last button, and all the lights in the room went out.

There was a grunt of surprise from the man with the spear, and general confusion from the remaining SHIELD agents and scientists. All the while though, Hiro snuck out from his hiding spot and crept closer to the blue light of the Tesseract.

_There's a case somewhere, just grab it and run, get it out of here safely, just-_

"Stop."

Hiro froze at the sound of the menacing voice.

"Don't think I don't see you, brat," the voice continued, and Hiro could see those malicious eyes glittering mere feet in front of him. "Now _step away_."

Hiro lunged for the Tesseract.

A loud _whoosh_ sounded as the man swung his spear, and Hiro felt pain sear through him. He crashed to the ground, head colliding against a fallen table, and then...darkness.

But several hundred miles away, a white vinyl robot looked up from playing with a cat and announced to the empty air, "Hiro is...gone."

o-o

...please don't kill me.


	5. Big Hero Five

**Um...hi, everyone.**

**Let me start off by saying that I am so incredibly, unbelievably sorry.**

**Has it been almost a year since I last updated? Yes.**

**Was I a bit of a meanie for leaving you at that cliffhanger? Yes.**

**Do I feel absolutely terrible? YES.**

**I am so completely honored by the love and support this fic has gotten; never did I imagine that I would get SO MANY favorites, follows, and reviews. You all are seriously the most wonderful people ever, and I feel like I've let you all down by leaving this story for so long.**

**I will say that I have a bit of an explanation for why I left, though you definitely still have the right to yell at me. I am a senior in high school, and between college applications, AP class work, finals, scholarship applications, college acceptances, and AP testing...I've been very busy and very stressed.**

**BUT NOW THAT IS ALL FINISHED. Which means that I should be able to get back to writing this story. Thankfully, I did not forget about this story's existence while I was away, and that has allowed me to not only plan out the rest of this fic, but some other lovely surprises and tie-ins to this whole universe that I am beginning to create.**

**Again, thank you so much for patiently and diligently waiting. I am so sorry, and I hope that you all enjoy.**

**And, as a disclaimer, I own nothing. I am going to be a college student, after all.**

o-o

"Hiro is gone."

There was the sound of a plate crashing onto the ground from the other end of the video call. "What do you mean, 'gone'?" Gogo hissed, shoving her way into the frame.

"I can no longer sense his vitals," Baymax replied. "The tracking band we gave him to monitor his health is inoperative."

Gogo glanced worriedly at the others scattered around the mansion's living room. Honey and Wasabi were sitting on opposite ends of the large red couch, while Fred was on the ground, cleaning up the remains of the shattered plate and reassembling the sandwich that had tumbled down with it. "Maybe the band's just...broken?" Honey offered hesitantly, glancing towards the video monitor.

"If it was broken, Hiro would have told us," Gogo retorted. She turned back to Baymax. "Has Hiro called you, or messaged you? Anything?"

Baymax blinked once, quickly scanning through his data base. "There have been no new emails," he said after a while. "And no new voicemails or text messages."

Gogo growled, hands curling into fists as she stalked away. "I knew this stupid SHIELD thing was a bad idea…"

"Whoa, hey, hey!" Wasabi scuttled after her, gently grabbing her shoulders. "Look, I know what you're thinking," he said. "But we can't just go assuming something bad happened to him! What if it's just bad connection, o-or the battery ran out? We can't go charging after him!"

"But what if something bad did happen?" Gogo snapped back. "What if Hiro needs our help?"

"She's got a point," Fred cut in, looking up from the ground. His face was startlingly serious. "Hiro would never leave us hanging like this if it wasn't bad."

Honey uneasily rose to her feet, clutching her purse tightly to her chest. "It's your call, Gogo," she said. During Hiro's absence, Gogo had been appointed the temporary leader of the team. "What do we do?"

A heavy silence stifled the room.

"Baymax," Gogo finally said, turning back to the video monitor, "meet us in the garage. Try to find anything that would help us locate Hiro." She looked over at the others. "The rest of you, suit up."

o-o

An hour later, the five burst into Hiro's cluttered garage workshop, clad in the colorful armor that had become a regular appearance around the city. "Baymax!" Gogo called out as she strode over, pulling off her helmet and popping her gum. "You find anything yet?"

Baymax tilted his head up slowly. "Oh, hello, Gogo." The robot pointed at a computer monitor, which was displaying a satellite image of California. A small red dot blinked in the southern part of the state. "I was able to trace the signal from Hiro's last video call," he explained. "He appears to have been in-"

"-the Mojave Desert," Honey finished, peering at the map. She looked over at the others. "That's not that far from here."

Gogo glanced at the cherry red armor tossed haphazardly into a pile in the corner of the garage. "Baymax," she asked sharply, "how fast can you fly there?"

Baymax straightened, lifting a finger for emphasis. "Estimated travel time: five hours and three minutes." A brief pause. "My batteries are 93% charged. I have enough energy to fly us there and back."

"Alright." Gogo turned to the rest of the team. "You heard him. Let's move!"

Within a few minutes, the team was soaring out past the San Fransokyo skyline, Gogo taking Hiro's usual place at the center of Baymax's back. The vibrant neon lights of the city blinked beneath them, soon turning into the soft yellow glow of the suburbs, soon turning to the rolling darkness of the barren valleys. Distantly, the bleak early morning light peaked over the clouded horizon, coloring the ocean but not yet reaching the mainland.

"We, uh, we almost there yet?" Wasabi asked, leaning over Baymax's wing to peer at the ground. His face immediately turned green, and he yanked himself back, squeezing his eyes shut.

"Remaining distance to destination: 2.4 miles," Baymax replied. There was a slight pause. "My sensors indicate that your blood pressure and heart rate have increased. Is it your fear of heights?"

Wasabi let out a nervous laugh. "Y-Yeah, buddy."

"Treatments for phobias and anxiety include-"

"Not now, Baymax," Gogo snapped curtly. "Keep scanning."

Baymax directed his attention back to the ground. A moment later, faint static crackled from his helmet. "There is some foreign energy in this area," he intoned. "It is interfering with my vitals sensor."

"Switch to the DNA scanner then," Gogo hissed.

"The DNA scanner is only in its test phases-"

"Do it!"

Baymax blinked once, tilting his head slightly upon seeing the crumbled ruins of several building beneath him.

"...one DNA match found."

o-o

The robot landed gently on a large chunk of concrete, the rubble shifting beneath them as the team scrambled off his back. "DNA match found," Baymax repeated, pointing towards one of the ruined buildings.

Wordlessly, Gogo slapped on her electromag discs and sped off. "Hey, wait up!" Fred shouted, bounding after her with Wasabi and Honey not too far behind. "Gogo!"

The skater wasn't listening to them, though. She had become an egg-yellow blur, speeding so fast her discs left scorch marks in the slabs of broken concrete. The desperate voices of her team crackled through the earpiece in her helmet, but they were lost to the wind; all she could hear was, _Hiro, Hiro, Hiro._

She had to find him. He had to be okay.

With one last burst of speed, Gogo reached the building Baymax had indicated, sparks flying as she skidded to a halt.

_Hiro, Hiro, Hiro._

She fell to her knees, digging through the rubble.

_Hiro, Hiro, Hiro._

There was a bright blue flash as Wasabi's plasma blade sliced through a bigger piece of concrete obstructing her path.

_Hiro, Hiro, H-_

Gogo stopped short, noticing battered suitcase protruding from the debris.

"Guys!" Gogo latched onto the handle of the suitcase and began to pull at it, Wasabi and Fred quickly joining her in her efforts. Gingerly, Baymax placed his armored hands on Gogo's torso, and with a gentle tug from the robot, the suitcase popped free from the pile of rubble.

"That's Hiro's bag," remarked Fred upon studying the suitcase. "See, it's got the fox label tag that Honey gave him when…"

Gogo pointedly ignored the rest of his anecdote. With shaking hands, she yanked at the zipper and threw open the suitcase, hoping to find something - anything - that would hint at Hiro's whereabouts.

All she found was a very familiar purple and red suit of armor.

"DNA match found."

Baymax pointed at the suitcase. Carefully, Gogo picked up the large helmet, noticing the strands of black hair caught in the joint of the visor. Memories of Hiro's high-pitched yelps as he repeatedly pulled out his wayward hair when trying to remove his helmet flashed across her mind. "Baymax must have detected the remaining hair follicle material," Honey observed.

Wasabi crossed his arms. "I didn't know Hiro had brought his suit with him," he said with a frown.

"He said he wanted it nearby, in case of an emergency," Honey explained softly.

The wind had begun to pick up, little chunks of debris swirling around the team of five. They stood as colorful sentries among the dark rubble, faces still and voices silent. Beneath their feet, they could almost hear the whispers of the dead describing what horrors had passed there. Clouds had drifted over the site of the wreckage, giving everything a grayish tint; the wind sounded hollow as it swept through the destroyed buildings. Gogo squeezed her eyes shut, resting her forehead against the cold front of the helmet. "It only works if you're wearing it, knucklehead," she hissed, her voice breaking midway.

Honey gently placed a hand on her shoulder. "C'mon, Gogo, we have to-"

"No!"

Gogo whirled around, eyes narrowed. "We have to keep searching for him," she ordered. "There has to be something-"

"Gogo," Baymax interrupted, "my scanners indicate that you are experiencing a sudden decrease in serotonin and increased levels of cortisol. Do you need medical assistance?"

"I'm fine!" Gogo snapped. "Just keep searching!"

The robot seemed to sigh. "There is nothing more I can do. Hiro is…"

He didn't finish the sentence. No one on the team wanted to hear it, anyways; not a single one of them wanted to face the finality of the fact. Hiro was gone, and they were powerless to help him.

Tentatively, Wasabi placed his hand on Gogo's shoulder. "Hey," he said, shaking her gently. "We should get going now-"

The faint buzz of helicopter blades cut him off. Slowly, like a swarm of ravenous flies, a horde of fighter jets and helicopters crept towards the wreckage site, their menacing forms silhouetted against the rising sun.

"That...does not look good," Fred remarked, bouncing nervously on his springs.

Honey looked over at the rest of the team. "What do we do?"

"Hold your ground," said Gogo. "Baymax can't outfly them with all of us on his back."

The five of them edged closer together, forming a protective circle. With a snap of his wrists, Wasabi activated his plasma blades; Honey warily grabbed a chemical ball from her bandolier. Four pairs of eyes and one set of hyperspectral cameras watched nervously as the fighter jets began to surround them.

"You are in a restricted government area," a voice boomed from one of the jets. "Identify yourselves."

Gogo stepped forward. "We are Big Hero Six of San Fransokyo," she called back. "We are looking for one of our own."

A pause. "Big Hero Six?" the voice repeated, less menacing and much more...eager. "Really?"

The team glanced nervously at each other. "Yes?" Gogo replied skeptically.

With a whir of the engines, one of the fighter jets dipped downwards, landing gently on a large, stable piece of concrete. The back ramp lowered, and a young man in a navy blue jumpsuit rushed out, pale blond hair sticking up wildly and dark eyes nearly popping out of their sockets. Hurriedly, he held up a battered badge.

"I'm Agent Williams, of SHIELD," he introduced himself. "We need your help."

o-o

**If anyone knows where Agent Willams is from, I will love you forever.**

**...who am I kidding, I love you all forever. You, dear readers, are the best. **


End file.
